1. Field of the Invention
The invention relates to products and methods for restoration of damaged conduits.
2. Related Art
Grout materials are often used to repair an interior surface of corroded, cracked, or otherwise damaged conduit. One method of repairing a metal conduit includes coupling short links of stainless steel sleeves to one another to form a liner, and pulling the stainless steel liner through the metal conduit with a cable to present a small annular space between the stainless steel liner and the metal conduit. A grout material is then pumped into the annular space to fill the annular space and cracks in the metal conduit. However, this method includes significant material costs and labor costs. Further, in the above method and other methods currently used, controlling the placement of the grout material is difficult. Oftentimes, the grout material is disposed unevenly along the damaged conduit and does not fill all of the cracks of the conduit.
Another more recently developed method for repairing damaged conduits with a grout material includes the use of an expandable pipe. The expandable pipe includes a liner and the grout material disposed in grooves along the exterior surface of the liner. The liner with the grout material is disposed in an opening of the damaged conduit, and then exposed to moisture such that the grout material expands and engages the interior surface of the damaged conduit.
The grooves of the liner allow for the expandable pipe to fold for convenient transportation of the expandable pipe. The grooves also provide flexibility for maneuvering the expandable pipe around bends of the damaged conduit. The grooves of the liner also allow for controlled placement and amount of the grout material along the exterior surface of the liner. The grooves maintain the placement of the grout material as the liner is disposed in the damaged conduit. The grout material expands to engage the interior surface of the damaged conduit and fills cracks, holes, indentations, or other imperfections and voids along the interior surface of the conduit, caused by corrosion, erosion, or other circumstances. In other words, the expandable pipe relines the interior surface of the damaged conduit. The expandable pipe also provides a seal to the conduit and prevents water and debris from entering the conduit. The grout material of the expandable pipe can also expand through holes in the conduit and fill voids in earth surrounding the conduit. The expandable pipe is a cost-effective and convenient way to repair and restore conduits of various types, such as sewer pipes, potable water pipes, electrical pipes, and air ducts. An example of the expandable pipe is disposed in U.S. Pat. No. 7,942,167.